This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Exocytosis is a process that eukaryotic cells use to move proteins contained in vesicles across the plasma membrane. Many proteins and protein complexes are required for the proper release of these vesicular contents outisde the cell and make up not only the physical machinery for transport, targeting and membrane fusion, but regluators as well. With better structural and functional understanding of how this system performs its function, a greater understanding can be achieved of how specific processes that rely heavily on exocytosis, such as neurotransmission and the recycling of proteins from the cell surface, occur and are controlled. Eventually, this information could lead to drugs developed to inhibit or promote these processes when they play a role in disease.